Honing machine



July 18, 1944. c. A. FULMER HONING MACHINE Filed May 4, 1942 INVENTOR. 1fiar/e6 f7 //rfzer [SW/7% ATTYS Patented July 18, 1944 UNITED STATESPATENT `FFICE t Y t 2,353,958` I HONlN G MACHINE Charles A. Fulrner,Waukegan, Ill. l

Application May 4, 1942, Serial No. 441,581

1r claims. (c1. 51-34) The present invention relates to honing ma-fchines and is directed to improvements in the automatic mechanism forcontrolling the movements of honing tools for machines of thischaracter. i y

Existing machines, which operate (en blind end cylinders for airplanemotors; 'or thelilef by simultaneously rotating and verticallyreciprocating their honing tools in contact with the work, are providedwith control systems which x the lower limit of motion of the honingtool to a constant and iniiexible position which' is adjacent to theextreme lowermost point of honing tool travel. Machines of this typemust therefore be equipped with an expensive elevating table so thatblind end cylinders, or other work being operated on by the machine,must be moved upwardly to a position in which the honing tool at itslowermost position of travel will operate onY the lowermost surfacewithin said work. This means of adjusting the work to the movement ofthe machine tool limits the use of the machine to a prescribed number ofcylinder lengths and therefore renders said machine unadapted to certaintypes of motor cylinders. The present invention solves this problem byemploying anni-1 versal honing machine which will operate on all sizesand types of cylinders thro-ugh mechanism for hydraulically adjustingthe lowermost limit of honing tool travel to the particular work to beoperated upon and by providing means for vary-` ing the lower limit oftool travel to any position within the maximum limits of motion of saidreciprocating tool and by the cooperation of said means with the othernovel features of the machine to be hereinafter more fully described.

Just before the fixed, lowermost limit ofA mo-V tion is reached by thetool on existing vertical machines, in its downward movement, areciprocating machine part to which the tool is fas'- tened strikes themain frame of said machine with physical impact thus creating e, shockand a vibration in said machine, to the honing tool and to the work,which is detrimental to them and to the eiiicient operation of saidmachine.' While the hydraulic system is being automatically ccnditionedto reverse the directionv of travel'v of said tool from a downwardlydirection to an upwardly one, the system continues. during this time,its tendency to move the honing tool in aY downwardly direction afterAsaid tool has been stopped by contact of the tool carrying part with themachine frame to thereby create a'honing tool dwell at the bottom of thereciprocating cycle of said tool. This dwell is necessary to pre-` venttaper of the cylindrical wall of a motor cylinder at its blind endbecause'the tool is prevented from traversing the area adjacent theretoas is well known ln-the art. A loss in machine efficiency results byphysically stopping the tool before the hydraulic system has beenconditioned to reverse the direction of movement of said tool. i

Furthermore, to obtain this honing tool delay before reversal of themovement of said tool, hydraulic reverse valves on conventionalmachinesare provided with means for restricting the drainage ow of uid from oneside ofvsaid valve when the machine has initiated unrestricted ow offluid pressure to the other sideof said valve. The means used forrestricting the ow of cil from the reverse valve to delay reversal ofthehoning tool and cause a dwell of said tool in the work, acts to directdrainage oil from said valve through any-one of a number of selective,re-

` temperature and its viscosity affects the rate of discharge throughany selected orice with a consequent variation in the time period ofdelay or,l dwell of the tool at the bottom of the stroke. With devicesof thisnature the time of honing tool dwell cannot be preciselycontrolled by the operators and there is little assurance that oncel thedwell period is determined upon and the machine adjusted thereto thatsaid dwell period will'y remain constant.

It is therefore an object ofthe invention to provide a flexible honingmachine for operating on blind end cylindersand the like, so that saidmachine will accommodate a wide rangek of cylinder lengths withoutadding to the initial cost' of said machine.

Another object of the invention is to provide a device for controllingthe lower limit of motion and the time of honing tool dwell at saidlimit which may be attached to existing machines'of the genera] typeillustrated herein which crisinally were not otherwise so equipped.

Another object of the invention is to provide a' taneously with thecompletion of said conditioning operation, to preclude, for apredetermined time, the introduction of pressure fluid to the hydraulicmeans whereupon said part is held in a pos-itive position at said limitof motion by a counterbalance valve automatically operated by theabsence of pressure uid in the hydraulic means.

A further object of the invention is to provide an improved andsimplified hydraulic system having incorporated therein the reversingmeans set forth in the foregoing object which provides increasedproduction capacity and high operating speeds for honing machines.

A further object of the invention is to provide a honing machine whichmore accurately locates a tool at the lowermos-t position of travel, inrelapressure to the cylinder may be of the type disclosed in my priorUnited States Patent No. 2,297,953, and may consist of a rack 2|fastened at its lower end to the coupling I and meshing with a gear 22.The gear 22 is adapted through suitable reduction gearing to rotate anoscillating control disk 23 which has stops thereon for engaging a lever24. The lever 24 operates the pilot valve which controls the reversevalve 26 as will be more fully explained below.

The pressure supply means comprises a motor driven pump 21 which takesfluid from the sump tank 28 and introduces it under pressure throughtion to the bore being honed, without impact or shock to the work ormachine parts, and which is also eflicient and of simplied design.

Another object of the invention is to provide an automatic timingdevicewhich will function to accurately retain a honing tool at its"dwell position over a denite predetermined time which is unaffected bytemperature changes or or other physical limitations.

Another object of the invention is to provide an easily and quicklyoperated device for setting the machine for any class of work to beoperated on, and which can be reset to the same conditions accurately atany future time.

A still further object of the invention is the provision of a devicecapable of changing the point of lowest travel to any place within thestroke capacity of the machine.

Other objects will be apparent from the following specincation anddrawing which illustrates a preferred embodiment of my invention and inwhich:

Fig. 1 is a diagrammatical view of the hydraulic system and essentialmachineparts of my honing machine, various parts thereof being shown incross-section and/or side elevation.

Fig. 2 is an enlarged, rear elevational view of the hydrostatic valveillustrated in Fig. 1.

Fig. 3 is a cross-sectional view taken on line 3-3 of Fig. 2.

The preferred embodiment of my invention comprises a machine frame 5which carries at its upper end a housing 6 in which a verticallydisposed tool carrying part 1 is journaled for rotation andreciprocation. The tool carrying part has a splined spindle 8 which islconstantly rotated through gears 9 by a motor (not shown). The lower endof said part is connected to an axially positioned tool head I0 by meansof a universal joint II; said tool beingV illustrated as operatingwithin the closed or ,blind end of acylinder I2 removably positioned ona base of the machine such as on the lower end of the frame 5. The upperend of the spindle is connected to a piston I3 by connecting rod. I6which is fastened at its lower end to the spindle by a coupling i5permitting rotation of the spindle relative to the connecting rod. Thepiston is reciprocated within a cylinder I6 to impart reciprocatingmotion to the tool carrying part by an hydraulic means which alternatelyintroduces fluid under pressure into the cylinder through upper duct l1and the lower duct I8 connected to pressure and exhausty lines I9 and 29respectively, said lines communicating with the fluid pressure reversingvalve and the pressure supply meansfor the machine.y

The mechanism associated with a moving part of the machine forcontrolling the hydraulic means which alternately introduces fluid underpressure supply line 29 to a hydrostatic control valve 3U which normallydirects said pressure uid through line 3| to the reverse valve and tothe lower duct I8 of the cylinder which, it will be noted, is connectedto the side of the cylinder through which the connecting rod passes.The'actuation of the reverse valve 26 is accomplished in the usualmanner through the pilot valve 25 which is connected to the pressureline 29 by a pipe 32, said pilot valve, upon oscillation throughalternately and simultaneously making lines 33 and 34 pressure and drainlines for moving a piston 35 to the right or lefthand side of thereverse valve 26, respectively.

The pilot valve is operated by a means responsive to the movement of thetool-carryingl part which automatically reverses the part betweenpredetermined limits prescribing its working cycle, said meanscomprising an oscillating disk 23 having a peripheral groove 3G in whichare adjustably mounted an upper, manually rotatable limit stop 31 and alower limit stop 38 which respectively determine the upper and lowerlimits of motion of the honing tool head during its working cycle withinthe cylinder I2. As illustrated by a broken line in Fig. 1, the pilotvalve may have a direct drive connection with the lever 24 whichoperatesthe pilot valve. The reduction gearing drive connection between the gear22 and the oscillating disk is such that the movement of the piston fromits maximum upper limit of motion to its maximum downward limit ofmotion creates an oscillation of the disk which is less than onerevolution, the working cycle of said tool head being controlled by thestops which are peripherally spaced apart on the disk at positions onsaid disk which determine the lower limits of motion of the tool head.The upper limit stop 31 engages a nger 39 on the pilot valve lever 24 tochange the movement of the tool carriage from an upward to a downwarddirection while the lower limit stop.38 has an extension 4I) thereon forengaging the finger 4| on the lever 24 for changing the movement of thetool head from a downward to an upward direction within the cylinderbeing operated upon. The lower limit stop 38 has a cam portion 43 formedintegral therewith and which is spaced a xed peripheral distancerfromthe extension 49 and engages electric switch 44 which actuates a valvemeans for stopping the tool at its lower limit of motion in the work.

In operation therefor, when the piston and the tool'carrying part are intheir upper inoperative positions with the tool head withdrawn from thework, actuation of the hydraulic pump 21 will introduce fluid pressurethrough line 3l into the reverse valve 26 which at that time would haveits piston 35 in the righthand side of the valve to permit introductionof said pressure fluid to lme I9 and into the upper duct of the cylinderis, thereby driving the piston downwardly. The

same iiuid pressure is also introduced into the line 720 and into thelower duct I8 of the cylinder I6, but the greater effective area on topof the piston I3, at which the pressure is introduced, will overcome thelesser pressure area beneath the piston I3, said area beneath the pistonbeing occupied by the connecting rod I4. The piston. therefore, willmove downwardly and force fluid from the lower end of the cylinder backthrough line 20 and into line I9 along with the pressure uid introducedto the reverse valve through line 3|. When the honing tool enters thecylinder to be operated on, the upper limit stop 31 is manually rotatedinto operative position (shown in Fig. 1) and the tool head continuesdownwardly in the work until the extension 40 on the lower limit stopactuates the pilot valve lever to reverse its motion by moving thepiston 35 to the position shown in Fig. 1 of the drawing. In thisposition pressure fluid is introduced through line 3I to the lower sideof .the cylinder while the line I 9 is made a drain line permittingdraining fluid to enter exhaust line 42 and return to the sump tank 28.The hydraulic system is now conditioned to initiate its movement of thetool head in an upward direction. At the moment of reversal, however, avalve means, including the hydrostatic valve 38 interposed between thepressure supply lines Z9-3|, is operated by an actuating meansconsistingof the cam 43 which operates a switch 44 to render the pressure supplymeans inoperative and stop the reciprocation of the honing tool at itslower limit of motion Within the work, thereby creating 'a dwell. Aselective time controlled means is also initiated by the actuating meansto provide a dwell of a selected predetermined time. A spring loadedcheck valve 260 interposed in line 29 assures that a given pressure willbe exerted at a point ahead of the hydrostatic valve 38 so that thereverse valve 26 can always operate even when the pressure is at zero inline 3 I.

The hydrostatic valve 39, as most clearly illustrated in Figs. 2 and 3,consists of a casing 45 provided with a passageway 46 which extendsthrough the bottom portion thereof and is connected to the pressuresupply line 3| at one side while the other side communicates withpressure line 29. A manually controlled rotary valve 111 is interposedin the passageway 46 and consists of a reduced semi-cylindrical part 48extending across the said passageway 46 and which is adapted to open orclose said passageway by manual rotation of a handle 49 connected tosaid valve by shaft 50. When the rotary valve is open the position ofthe semi-cylindrical portion relative to the passageway 46 determinesthe volume of pressure fluid admitted to the line 3l from the pump.

As most clearly shown in Fig. 3, a cylindrical chamber I is disposedabove the rotary Valve which communicates at its forward end with thefluid pressure line 29 on the pump side of the rotary valve by means ofa passageway 52 (Fig. 2) while the rear end of the chamber communicateswith the pressure supply line 3| on the motor cylinder side of saidrotary valve by a passageway 53. A movable valve member 54 is positionedwithin the chamber 5I intermediate the ends thereof so that pressurefluid may be introduced through said passageways 52 and 53 to opposedsides of said member which takes the form of a piston 55. Extending fromsaid piston 55 into the forward end of the chamber is a valve head 56which is adapted to Vopen and close an exhaust port 51 formed in thecasing45`and which communicates with the pump side 29 of the pressureline through passageway 52, said exhaust port being connected to thesump tank 28 by line 58. The valve member is biased to close the port 51by a spring 59 which encircles a' guide shaft 60 extending into a guideopening 6 I formed in the rear portion of the chamber.

As indicated in Fig. 3, a ball check valve 62 is interposed in apassageway 63 which connects the rear part of chamber 5I with theexhaust line 58, a spring 64 and set screw 65 being adapted to adjustthe static pressures in both ends oi' the chamber 5I. This ball checkvalve permits the return of pressure iiuid back to the sump tank 28'whenthe machine is manually shut down by closing the rotary valve 41. Whenva1ve`41 is closed maximum pump capacity is introduced to the forwardend of the chamber 5I through line 29 and passageway 52. This pumppressure exertedon the forward side of the piston 55 is greater than thecombined pressures of the fluid in the cylinder end of the piston andthe spring 59 exerted on the rear side of said piston and is alsosufficient to unseat the ball check valve 62. The piston 55 is thereforemoved to unseat the valve head 56 and fluid pressure from the pump isdelivered to the sump tank A28 through line 58.

In normal operation, therefore, the rotary valve will be set to permitflow of pressure fluid' from the pump 21 through line 29 and into thepressure supply line 3| for the hydraulic system and said pressure fiuidwill enter the vvchamber 5I and create static pressure on opposed sidesofy the piston 55 of the valve member, the spring 59 serving to biassaid piston to close the exhaust port 51. A pressure release means 66which takes the form of a solenoid valve controls the passage ofpressure fluid from the rear portion of the cylinder through an exhaustline 61 connected to said chamber and the valve 66. As shown in Fig. l,the valve has a plunger 68 which is spring urged to closed positionagainst the valve seat 69' which prevents fluid from exhausting throughline 10 into exhaust line 42. The valve is opened by the actuation of asolenoid 1I which is connected to the plunger 68 by a shaft 12, saidsolenoid being actuated when the switch 44 is closed by camming of thedog 38 on the oscillating disk. When the solenoid valve is so operated,the uid pressure in the rear side of piston 55 is reduced to zero whilethey iluid pressure in the forward side of the chamber is the pressurein the pump side of the Aline 29 which moves said piston 55 against thebias of the spring 59 and permits all of the pressure fluid from thepump 21 to be re- Y turned to the tank through the port 51 and exhaustline 58. When the pressure release means is actuated by the switch 44,the honing tool has come to rest in its lowermost limit of motion withinthe work (Fig. 1) by the reversal of the hydraulic system from adownward to an upward tool carrying condition. At said instant ofcomplete reversal tbe solenoid valve 66 is operated, thus returning allof the pressure fluid from the pump to the sump tank and therebyrendering the pressure' supply line 3| incapable of carrying pressurefluid. Line 20 also has a zero pressure in it and therefore acounterbalance valve 13 is interposed in said line between the reversevalve 26 and the lower duct of the cylinder I8 to hold the reciprocatedweight stationary. This valve holds the reciprocated part of the machinestationary regardless of the position at which said parts come torestand consists of a passageway A'|4 exten'dingthrough said valve inwhich a plunger is Seated, said plunger having disk-like heads ofunequal diameter. VThe upper head of the plunger has the greatestdiameter so that pressure uid inline will unseat said plunger and allowfluid to enter the cylinder I6. The plunger is urged to seated positionby aV spring 16 which can be adjustably compressed by threaded boss Thepressure exerted by the spring is adjusted to be more than enough toretain fluid in the lower side of the cylinder when line 20 has zeropressure therein to sustain the reciprocated mass in a stationaryposition.

As shown in Fig. 1, the one side of the solenoid valve 66 is connectedto the switch 44 by electric line '18 while the other side of saidswitch is connected to an electric power line 19 by line 8l). The otherside of the solenoid valve is connected to va normally open switch 8| bya line 82, the

other side ofthe switch being connected to the power line 19 by line 83.i

It is also contemplated that the elapsed time during which the tooldwells in its lowermost limit of travel within the work can beselectively controlled and that this time of dwell may be preferablyaccomplished by means of a pneumatic timer 84 which is conditioned foroperation by the closing of the switch 44 and which is adapted to breakthe connection between the switch 44 and the solenoid valve 66, after anelapsed period of time, by the opening of switch 8|. The pneumatic timerhas a solenoidV 85 positioned on the casing and connected to the circuitleads 18 and 83 through switch 44 so that upon actuation of saidswitchthe solenoid will for an instant be actuated to draw up thearmature 86, thereby moving upwardly the block 81 and ilexible diaphragmB8 against the bias of spring 89. This action closes the switch 8| andalso exhausts air in the upper chamber 90 of the timer through a one-wayvalve 9|. After the actuation of the solenoid, the contact block and thediaphragm move downwardly at a rate dependent upon the amount of airpermitted to enter saidchamber 9!) through needle valve 92 which isadjustably controlled by a threaded pin 93. The block, upon reaching itslowermost position indicated in Fig. 1, contacts an arm 94 which opensthe switch 8|, thereby breaking the connection between the switch andthe solenoid valve 66 and permitting said valve to move to closedposition under the action of its biasing means. When said solenoid valveis closed, pressure is again built up in the rear end of the chamber ofthe hydrostatic valve which permits the piston 55 to move to the left(Fig. 3) under the bias of the spring 59 and close the port 51' to theexhaust. Pressure fluid is then permitted to move into the hydraulicsystem through supply line 3| thereby raising the honing tool within thework and continuing the working cycle of the machine.

What is claimed is:

l. In a honing machine the combination of a rotating and a verticallyreciprocating tool carrying part, a vertical cylinder disposed above thepart in axial alignment therewith, a piston in the cylinder, aconnecting rod for the piston and the part, an hydraulic reversing meansactuated by the reciprocating part for changing the direction ofmovemento said part, an upper and a lower duct for the cylinder, an'hydraulic line connected to each duct and communicating with thereversing means, pressure supply means interposed in the line for thelower duct, said reversing means acting during upward movement of thepart to drain fluid from the upper duct and to permit introduction ofuid direct from the pressure supply means to the lower duct, and duringdownward movement of the part acting to introduce fluid under pressureto the upper duct from the lower duct and from the pressure supplymeans, valve means associated with the pressure supply means forrendering the last said means inoperative, actuating means operated bythe part and having an operative connection with the valve means, aselective time controlled means associated with 'the actuating means forbreaking the connection between the actuating means and the valve meansafter the elapse of a predetermined time, and a counterbalance valve inthe line to the lower duct between the pressure supply means and saidduct for preventing the draining of fluid from the lower end of thecylinder when the valve means renders the pressure supply meansinoperative.

2. In a honing'machine the combination of a rotating and a verticallyreciprocating tool carrying part, a cylinder, a piston in the cylinder,a connecting rod for the piston and the part, hydraulic means foralternately introducing fluid under pressure to opposite ends of thecylinder to reciprocate the piston and the part, a pressure supply linefor the hydraulic means, valve means associated with the pressure supplyline and comprising an exhaust port connected to the supply line, amovable valve member, means for biasing the valve member to close theport, means for introducing fluid pressure from the supply line toopposed sides of the member, and pressure release means communicatingwith one side of the member, actuating means operated by the part andhaving an operative connection with the pressure release means, andselective time controlled means associated with the actuating means forbreaking the operative connection between the actuating means and thepressure release means after the lapse of a predetermined time. v

3. In a honing machine the combination of a rotating and a verticallyreciprocating tool carrying part, a vertical cylinder disposedabove the`part in axial alignment therewith, a piston in the cylinder, aconnecting rod for the piston and the part, an hydraulic reversing means'actuated by the reciprocating part for changing the direction ofmovement of said part, an upper and a lower duct for the cylinder, anhydraulic line,

connected to each duct and communicating with the reversing means, apressure supply line interposed in the line for the lower duct, valvemeans associated with the pressure supply line and comprising an exhaustport connected to the supply line, a movable valve member, means forbiasing the valve member to close the port, means for introducing uidpressure from the supply line to opposed sides of the member, andpressure release means communicating with one side of the member,actuating means operated by the part and having an operative connectionwith the 'pressure release means, and selective time controlled meansassociated with the actuating means for breaking the operativeconnection between the actuating means and the pressure reease meansafter the lapse of a predetermined 4. In a honing machine thecombination of a rotating and a vertically reciprocating tool carryingpart, a vertical cylinder disposed above the part in axialalignmenttherewith, a piston in the cylinder, a connecting rod for thepiston and the part, anhydraulic reversing vmeans actuated by thereciprocating part for changing the direction of-'movement of saidpart,an upper and a lower duct for the cylinder, an hydraulic lineconnect- `ed to each duct and communicating with the reversing means, apressure supply line interposed in the line for the lower duct, valvemeans associated with the pressure supply line and comprising an-exhaustport connected to the supply line, a movable valve# member, means forbiasing the valve member to close the port, means for introducing fluidpressure from the supply line to Yopposed sides of the member, andpressure release means communicating with one side of themember,"actuating means operated by the part and having an operativeconnection with the pressure release means,-selective time controlledmeans associated with the actuating means for breaking the operativeconnection between the actuating means and the pressure release vmeansafter the lapse of a predetermined time, and a counterbalance valve inthe line to the lower duct betweenthe pressure line connection and saidduct for preventing the draining of fluid fromr the lower end of thecylinder when the valve means renders the pressure line inoperative. l

5. In a honing machine the combination of a rotating and a verticallyreciprocating tool carrying part, a` cylinder, a piston in the cylinder,a connecting rod forfthe piston and the part, an oscillating diskconnected to the part, upper and lower limit stops on the disk, anhydraulic reversing means actuated by the stops for changing thedirection of movement of said part dur-- ing its working cycle, an upperand lower duct for the cylinder, an hydraulic line connected to eachduct and communicating with the reversing means, a pressure supply lineconnected toy the hydraulic line for the lower duct, valve meansassociated with the pressure supply line and comprising an exhaust portconnected to the supply line, a movable valve member, means for biasingthe valve member to close the port, means for introducing pressure fluidfrom the supply line to opposed sides. of `the member, an exhaust linecommunicating with one side of the member, a solenoid valve interposedin said exhaust line, an electric switch actuated by the stopcontrolling the lower limit of motion of the part and having anoperative connection with the solenoid valve, and a selective timecontrolled means for breaking the operative connection between theswitch and the solenoid valve after the lapse of a predetermined time.

6. In a honing machine the combination of a rotating and reciprocatingtool carrying part, a motor for the part, hydraulic means foralternately introducing-pressure fluid Lvto opposite ends of the motorto reciprocate the part, a pressure supply line for the hydraulic means,valve means associated with the pressure supply line and cornprising achamber, a piston positioned in they chamber intermediate its ends,passageways for each end of the chamber and each communicating with thepressure supply line, a volume control valve interposed in the pressuresupply line between said passageways, an exhaust port in one end of thechamber, means for biasing the piston to close the port, a ball checkvalve between the chamber ends, pressure release means communicatingwith one side of the chamber, and actuating means operated by the partand hav- `ing an operative connectionwith the pressure remotor for thepart, hydraulic means for alternatelyintroducing,pressureuid to oppositeends of the moto'rto reciprocate the part, a pressure -supply line for.the hydraulic means, valve'means associated with the pressure supplylineand comprising -a chamber, a pressure responsive device positionedthe chamberintermediate its ends, means for introducing fluid pressurefrom the supply line to opposedsides of the device, a volume controlvalve interposed on the pressure supply line between the said means, anexhaust port'in one end of the chamber, means for biasing the device toclose the port, a relief valve between the chamber ends, pressurerelease means communicating withoneside of the chamber, and actuatingmeans operated'by the part fand having an operative connection with thepressure release means. c

8. In a honing machine the combination of a rotating and a verticallyreciprocating tool-carrying part, a vertical cylinder disposed above thepart, a piston in the cylinder, a connecting rod for the pistonand thepart,hydraulic means for alternately introducing pressure fluid to theupper and the lower endof the cylinder to reciprocate the part, pressuresupply means for the hydraulic means, means responsive to the movementof the part connected with the 'hydraulic means and adapted to controlthe upper and lower limits of motion of the part during its workingcycle, valve means associated with the pressure supply means, actuatingmeans operated by the means responsive to the movement of the part andmaking an operative connection with the valve means when said part is atits lower limit of -motion to render said supply means inoperative, acounterbalance valve communicating with the lower end of the cylinderfor preventing the draining of fluid from said cylinder end when thevalve means renders the pressure supplymeans inoperative and a timecontrolled means for breaking the connection between the actuating meansand the valve means after the elapse of a-predetermined time.

9. In a lhoning machine the combination of a rotating and reciprocatingtool-carrying part, a cylinder, a piston in the cylinder, a connectingrod for the piston and the part, pressure supply means for the hydraulicmeans, means responsive to the movement of the part -connected with thehydraulic means and adapted to control the limits of motion of the partduring its working cycle, valve means associated with the pressuresupply means, a solenoid for the valve means, a switch operated by themeans responsive to the movement of the part and actuating the solenoidwhen said part isat a limit of motion during its working cycle to rendersaid supply means inoperative, and a time controlled means conditionedfor operation b-y the actuation of the switch and adapted to break theelectrical connection between the switch and the solenoidafter theelapse of a predetermined time.

10. In a honing/machine the combination of a rotating and reciprocatingtool-carrying part, a cylinder, a' piston in the cylindena connectingrod for the piston and the part, pressure supply means for the hydraulicmeans, means responsive to the movement of the part connected with thehydraulic means and adapted to control the limits of motion of the partduring its working cycle, valve means associated with the pressuresupply means and normally closed to permit the introduction of pressurefluid to the hydraulic means,

a solenoid for Opening the valve means to render said supply meansinoperative, a selective time controlled means, a solenoid forinitiating the operation of the time controlled means, a switch operatedby the means responsive to the movement of the part ,and actuating thesolenoids when said part is at a limit of motion during its workingcycle, and a means actuated by the time controlled means after apredetermined time to break the electrical connection between the switchand the valve operating solenoid to return the valve to normal position.

11. In a honing machine the combination of a rotating and areciprocating tool carrying part, an hydraulic motor connected to thepart, hydraulic means for alternately introducing fluid `under pressureto opposite ends of the motor to reciprocate the part, a pump fornormally supplying pressure fluid to the hydraulic means, valve meansinterposed between the pump and the hydraulic means for precludingintroduction of pressure fluid to said hydraulic means, actuating meansoperated by the part and having an operative connection with the valvemeans, selective time controlled means associated with theactuatingmeans for breaking the connection between the actuating means and thevalve means after the elapse of a predetermined time, and means in thehydraulc means for Vprecluding draining or fluid from one end of themotor when said valve means is operative.

12. In a honing machine the combination of a rotating and a verticallyreciprocating tool carrying part, an hydraulic motor connected to thepart, hydraulic means for alternately introducing fluid under pressureto opposite ends of the motor to reciprocate the part, a pump fornormallysupplying pressure huid to the hydraulic means, valve meansinterposed between the pump and the hydraulic means for precludingintroduction of pressure luid to said hydraulic means, actuating meansoperated by the part and having an operative connection with the valvemeans, selective time controlled means associated with the actuatingmeans for breaking the connection between the actuating means and thevalve means after the elapse of a predetermined time, and means in thehydraulic means for precluding draining of fluid from one end of themotor when said valve means is operative.

13. In a honing machine the combination of a rotating and a verticallyreciprocating tool carrying part, a cylinder, a piston in the cylinder,a connecting rod for the piston and the part, hy-

draulic means for alternately introducing lluid under pressure toopposite ends of the cylinder to reciprocate the piston and the part,pressure supply means` for the hydraulic means, valve means associatedwith the pressure supply means for rendering the last said meansinoperative, actuating means operated by the part and having anoperative connection with the valve means, means interposed in thehydraulic means to the lower end of the cylinder for precluding.draining of fluid therefrom when the valve means is operative, andselective time controlled means associated with the actuating means forbreaking the.

connection between the actuating means and the valve means after theelapse of a predetermined time,

14. In a honing machine the combination of a rotating and a verticallyreciprocating tool carrying part, an hydraulic motor connected to thepart, an oscillating disk driven in timed relation with the part, upperand lower limit stops on the disk, an hydraulic reversing means actuatedby the stops for changing the direction of movement of said part duringits working cycle, an upper and lower duct for the motor, an hydraulicline connected to each duct and each communicating with the reversingmeans, a pump line connected to the reversing means for normallysupplying fluid pressure to the hydraulic lines, valve means interposedin the pump line for precluding introduction of pressure fluid to thereversing means, a solenoid for operating the valve means, a switchactuated by the stop and controlling the lower limit of motion of thepart and having an operas tive connection with the solenoid,'a selectivetime controlled means for breaking the operative connection between theswitch and the solenoid after the elapse of a predetermined time and acounterbalance valve interposed in the hydraulic line to the lower endof the motor for precluding the draining of fluid therefrom when thevalve means is operative.

15. A honing machine as claimed in claim 14 wherein the upper and lowerlimit stops are adjustably mounted adjacent the periphery of the diskand said lower limit stop has a switch operating cam and an extensionfor engaging the reversing means which are disposed in fixed, spacedrelationship.

16. A honing machine as claimed in claim 14 wherein the reversing meansand the switch are disposed in xed spaced relationship, and the lowerlimit stop on the disk has a switch cam and an extension for contactingthe reversing means each rigidly mounted thereon in spaced relationship.

17. In a honing machine the combination of a rotating and areciprocating tool carrying part, a motor for the part, hydraulic meansconnected to the motor, v a reversing valve for the hydraulic means, apiston in the reversing valve adapted for movement between two positionsfor reversing the movement of the part at its limits of reciprocatorymotion, means associated with the part foractuating the piston, a pumpfor normally supplying pressure uid to the hydraulic means, valve meansinterposed between the pump and the hydraulic means, actuating meansoperated by the part and adapted to operate the valve means uponcompletion of the piston reversal for precluding the introduction ofpressure fluid to said hydraulic means, a counterbalance valve actuatedby the absence of pressure in the hydraulic means and adapted to holdthe part at its said limit of motion, and a time controlledmeansassociated with the actuating means for breaking the connection betweenthe'actuating means and the valve means after the elapse of apredetermined time to permit introduction of pressure fluid to thehydraulic' `means under the control of the reversed piston positionofthe reversing valve.

CHARLES A. FULMER.

